Radiotelegraphy.



L. F. FULLER. RAD|0TELEGRAPHY. APPLICATION FILED MAR. 21, ms.

1,3 OO,1 57, Patented Apr. 8, 1919.

' lllllm' H/6 ATTORNEYS.

UNITED STATES PATENT onrrcn LEONARD F. FULLER, OF-SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO FEDERAL TELEGRAPH COMPANY, OF SAN FRANCISCO. CALIFORNIA, A CORPORATION OF CALIFORNIA.

mnro'rntncnarnr.

Patented Apr. 8, 1919.

Application filed March 27, 1916. Serial No. 86,935.

To all whom, it may concern:

Be it known that I, LEONARD FQFULLER, a citizen of the United States, and a resident of the city and county of San Francisco, State of California, have invented certain new and useful Improvements in Radiotelegraphy, of which the following is aspecification.

The invention relates to transmission systems of radiotelegraphy'and particularly to a means of signalin An object of the invention is to provide a signaling system for high powered transmission stations.

The invention possesses other advantageous features, which, with the foregoing, willbe set forth at length-in the following description, where I shall outline in full that form of the invention which I have selected for illustration in the drawing accompanying and forming part of the present specification. In said drawing I have shown only one specific form of my invention, but

it is understood that I to such form.

In the drawing I have shown diagrammatically one form of transmission system of my invention. The system includes a suitable source of oscillations, preferably continuous oscillations, such as the are 2 which isinclosed in ahydrogen atmosphere. Current is furnished to theme by adirect current generator 3. One sideof the arc is grounded by the conductor 4 and the other side is'connected to the radiating conductor or antenna 5, through thevcond'uctor 6 and the variabl inductance 7. Signaling 'has heretofore frequently been effected by varying the wave length-of. the radiated wave, by short-c'ircuiting a portion of the inductance, but in high powered stations the curdo not limit myself rent in the short circuit is large,'making sig-' naling difficult.

. In accordance with the I provide a circuit containin an inductance 8, a capacity 9 and a variab e resistance 12, which is shunted around the are 2. The resistance 12 comprises an arc, the spacing of the electrodes of which is preferably such that normally a very small amount of cur rent will pass across the are, making the shunt circuit practicallynn 0 en circuit and confining the oscillations tot e antenna cirpresent invention,

cuit. The resistance of the are gap is preferpressing an additional voltage on the are 12,

to reduce the resistance thereof and form a path for the current from the arc 2. Shunted around the arc 12 is a circuit containing a source of E. M. R, such as a direct current generator 13 and a signaling key 14 which is preferably provided with a magnetic blowout orother arc extinguishing means. The generator 13 may produce a current of 500 volts, which when impressed on the are 12 causes the gap to be bridged, so that the current from the generator 13 forms a bridge over which the current from the are 2 passes. Closing the key 14 will therefore operate to close the shunt circuit around the are 2 thereby causing the shunt circuit to become the oscillations to be confined to the antenna circuit.- The are 12 is preferably provided with a magnetic blowout which extinguishes the are 12 when the key is opened.

' I claim:

1. In a radiotelegraphy transmission system, an are, a radiating conductor connected to one side of said are, a grounded conductor connected to the other side of said arc, a circuit containing capacity, inductance and a gap shunted on said arc, a source of current connected to opposite sides of said gap and a key for controlling the flow of said current.

An are system for radio signaling comprlsing an antenna c1rcu1tand an absorption circuit both in parallel and shunted across the arc and means for varying the vibrationperiod of the absorption circuitcomprising a gap in said circuit and means for va'ryin the electromotive force impressed on sai gap, so that the gap may be opened or closed to the fiow of radio-frequency current from the arc.

' In testimony whereof, I have hereunto set In presence of i H. G. Pnos'r.

as V,

my hand at San Francisco, California, this 

